Air-powered miniature airplane



'Apn] 20, 1954 N. E. WALKER 2,676,013

AIR-POWERED MINIATURE AIRPLANE v v Filed July 25, 1951 2 Sheets-Sheet l INVENTOR.

Nvl'lle E.Wa [ker- April 20, 1954 N. E. WALKER 2,676,013

AIR-POWERED MINIATURE AIRPLANE Filed July 23, 1951 2 Sheets-Sheet 2 INVENTOR.

E]. Nevi He E. Walker iE',

Patented Apr. 20, 1954 UNITED STATES OFFICE 2,676,013 AIR-POWERED' MINIATURE AIRPLANE Neville 'E. Walker, Portland, "Oregg, assignor' to American Junior Aircraft-Company, Portland, reg., incorporation of Oregon AppIication'JuIyZ'S, 195-1,-'-Serlal N 0. 238,117

6 Claims.

I l This 'invention relates to a captive-type miniatiire' airplane having an air motor propelling mechanism which is joined, by-meansof anelongated'hollow' air tube, to a distantlylocated source of Fairtsupply, ther'eby to actuate the motor and to limit the flight path of the airplane from -a distance with the same hollow air tube member.

Oneobje'ct'of my inventionis to provide a miniatureairplane-Which is propelled by an air motor controllable from a distance' thereby to decrease or obviate the necessity of an-operator standing in'the' center of a' circle and turning more or'less rapidly as the airplane follows a circular path as Well as'to eliminate'noise incident to th'eilight of internal combustion engines provided forseH-propelled miniature toy. airplanes hitherto known. These advantages, in summation, provide a miniature :air plane'of'peculiar adaptation to th'e requirements of indoor fiying.

In'the "-marketin'g' of toy. or miniature aircraft, two main types ofretail outlets are utilized. Firstly; hobby and toy shops and -handicraft and sporting goods stores provide a 'year around outlet patronized principally "by school age children and young adults. Secondly, department and variety stores sell a larg volume of this merc'handise, mainly totheparents of school age children, during the Christmas rush season. During therema'ind'er-of the season, of course, theselatter outlets continue their'sales but the voliu'n'e is much laii'ger at Christmas time.

In anticipation of the seasonal trend in hobby and toy sales, many department stores allot a floor space and'a'demonstration' staff toth'ese products duringthe latter part of November and during December, Furthermore, individual distributors and manufacturers are allotted floor space to install exhibits by'which they maydernonstrate their wares: This is an exceptiona'llysatisfactory marketingmethod and increases the sales volume materially. However; thismarketing method hitherto has been unavailabl: to 'the' manufacturer or distributor of self-propelled l miniature airplanes becaus of the natu're of the'product. Thus, such airp'lanesconventionally are powered by. midgetgasoline or dieselengi'n'es, relatively heavy'in'weightand very noisy'in operation. In fact, the noise from a typical miniatureairplane engine is deafening in a crowded'department storeand the fire hazard and danger of collision with customers, salespeople, and articles'on displayhitherto have prevented theactiv'e indoor demonstration"of captive airplanes; In obvi'ation 0t {thesedanger'sand improvement on the prior an; captive" airplanes; it is oneobject of 5 my 'inr of the tube.

toyor handicraft material which their clerks cannot personally demonstrate; will agreetosell the instant miniature airplane; Accordingly, the firstprime advantage of my ;invention-is one of increased commercial-ivalue or-sales volume as bottomed upon the provision forindoor flight, especiallyin' department stores and more-particuiarly during the season-of large volume sales.

Progressing .tothe-second prime advantage of thisiimproved structureyaminiature airplane constructed in accord with mytinventive concept includes-an 'air motor having the first end of an elongated; hollow ":air "-tube" connected therewith. Located distantlyv from the airplane; a fixed pylon member releasably holds an intermediate portion Thus; that portion -.of the air" tube carried intermediate the pylon and the airplane serves to limit theiflight of the Ea-irplane-to a circular path about th' 'pylflll2.331-(36I1'b812 Additionally, a second or terminal .end of the hollow air tube is connected across a control 'or throttle vawewith-an air pressure supply, such as an air bottle, compressor, or hand pump accumulator. T-wo' option'al 'meth'o'ds of "flight control are possible with this combination pylonstructure First ly, the aifsupplyandathe control valvemay be placedoutside the radius of the 'fiight circle to allow a continuous visual observation :of the airplanein flight: vSecondly; the-supply and control actuation mechanism may be located adj acent the baseof the pylori, and the latter may extend vertic'ally up above the'head of the operator. This alIows the'-'operator to manipulate the control, which manipulation may simulate that of an actual airplane throttle; without having continuously to counteract the centrifugal force or outward pull of the miniature airpl-ane;'- This force and pull are a disadvantage verymuchiin evidence in the-prior "art;

To" secure yet a -third inventive advantage or objective theaforementionedstructure may be combined witha pneumatic mechanism; including a seoond', -parallel hollow air'tube' to control' the elevators, rudder; an'clior aileronsof the miniature airplane Fat the saifie the air motor is controllflr optionally; thi's' structural addition with a miniature airplane I.

appear in th following detailed description, talgen in conjunction with the accompanying drawings,

wherein: U

Fig. 1 is a perspective view of a miniature airplane which is equipped both with an air motor and with a pneumatic control, the latter being shown as it is applied to the elevator;

Fig. 2 is a side view, somewhat schematic, indicating the manner in which an elongated hollow air tube may function as a flight limiting means to cause a miniature airplane to fly in a circle about a fixed pylon; said figure further indicating an optional location for the actuation mechanism, such location being shown outside the radius of the circular flight path for the miniature airplane;

Fig. 3 is an enlarged view, partially foreshortened, indicating the details of my verticallyextensible, fixed pylon guide which may be ut1l1zed when the miniature airplane operator does not wish to turn and rotate as the airplane flies in a circular path; and

Fig. 4 is an enlargedside view, partially foreshortened, illustrating a preferred form of my actuation mechanism wherein a miniature control stick and throttle are operable to simulate 'the movements of the control stick and throttle in an actual airplane.

In the drawings accompanying this specification, I have shown my invention in combination This particular airplane includes an elongated fuselage 2, an integral main wing 3, a fixed vertical rudder 4, a horizontal stabilizer 5, and an adjustable elevator 6. As will become apparent during the development. of this specification, however, my

invention is equally practical in combination with a miniature airplane having fixed elevators and/or an adjustable rudder and/or adjustable ailerons.

That is to say, the particular details of the miniature airplane per se are relatively unimportant to the scope of the instant invention so long as an airborne structure is provided.

As is functionally illustrated in the perspective View of Fig. 1, the airplane I is provided with an air motor I operatively connected to a propeller 3 for powering the airplane in flight.

This motor 1 may be of any conventional design, such as a piston and cylinder or turbine type, -so long as it functions to rotate the propeller when air is supplied thereto. elongated, hollow air tube 5 is connected with Y the air motor I to supply air thereto. This tube One end of an 9 and the air motor I are best made of light weight materials to facilitate the flight of the airplane.

Progressing outwardly along the main wing 3, a guide clip It is detachably secured to the wing and this clip is adapted to receive an intermediate portion of the air tube 9 in an aperture formed therethrough. Preferably, the guide clip IE3 is crimped to or frictionally slipped over the main wing 3 so it easily may be removed for 'reattachment to the opposite side of the wing. .In general, such reattachment may be required periodically so the air tube 9 can be unwound a by flying the airplane in an oppositely directed circular path.

In Fig. 4, I have shown an air supply mechanism in the form of an air bottle II which is utilized to supply air under pressure to the m0- tor I. If desired, an air pump (not shown) may be provided to recharge the bottle periodically. This bottle is connected, through a vertical pipe I2 and across a control valve l3, to the aforementioned air tube 9. The vertical pipe I2 stands upon a base It which is best fabricated from a section of hollow tubing to accommodate an intermediate portion of the air tube 9. Additionally, the control valve I3 is provided with a throttle lever I5 which is pivotally mounted for movement back and. forth in simulation of the movements of the throttle of a full-scale airplane. That is to say, the throttle lever I5 is shown in an intermediate position, wherein a slight volume of air is allowed to flow from the air bottle I I, through the vertical pipe I2, across the valve I3, through the air tube 9, and out to the air motor 7. However, the lever I5 may be moved through the are It to define a full open position for the control valve I3, or it may be moved through the are H to define a closed position for the control valve I3. This latter position is equivalent to a shut off of the air supply through the tube 9 and the motor 7 thereby is stopped.

The operation of that portion of my invention above described will be set forth with reference to a demonstration flight in a department store. Thus, the control surfaces of the airplane I may be set to define a laterally and longitudinally stable flight of the airplane commensurate with the limitations imposed upon that flight by the length of the air tube 9. That is to say, the'air tube 9, when under tension, acts as a flight limiting line to cause the airplane I to describe a circular flight pattern about the base member I4 and associated mechanism as a center. Initially, the operator grasps the base member I4 in one hand and, with the other hand, the throttle lever I5 is moved through the arc IT to the position shown in Fig. 4. This movement opens the control'va-lve I3 to supply air to the air motor from the air bottle I I. As the airplane takes oif, it rises in altitude according to the speed of the motor I as controlled by the valve I3. As will be apparent to those familiar with air-motors and with the conventional gasoline or diesel miniature airplane motor, all fire hazards are obviated by use of the instant invention. Furthermore, the operation of the air motor I is relatively silent as compared to the-deafening noise made by an internal combustion engine. Still further, since the air motor I can be made lighter in weight than the conventionalinternal combustion engine, the airplane I is required to lift less weight, and there is less danger that articles about the department store will be broken should the airplane I come in contact therewith. As will now be apparent, that portion of my invention so far described may be fabricated at a low cost and the entire flight pattern is controlled by the manipulations of the throttle valve via the lever I5 per se. 7

As an optional method of flying the airplane l and as an optional structural feature, the pylon guide It of Fig. 3 may be employed. This pylon includes a fixed base I9 carrying an upstanding tubular member 26 into which is teleindicates, an intermediate portion of the elongated, hollow air tube 9'is threaded throuh' the tubular member 20 and 2!. Furthermore, an adjustment member orcap '22 is provided to allow vertical adjustment of the height of the pylon l8. Thus, 'the pylon guide l8 releasably holds an intermediate portion of the air tube 9 so that portion of the air tube intermediate the airplane and pylon will limitthe flight of the airplane to a circular path about the pylon as a center (see Fig.2).

a continuous visual observation oi the airplane Secondly, the control and .in flight is possible. actuation mechanism may be located at the base of the pylon I 8. If this isdone, the pylon should be extended vertically above the head of the operator "as by backing on the adjustment cap 22 and extending the small tube 2. During this second method of flying, the airplane I will fly a circular path-about the pylon as a center and the operator must turn his head, at least, with the flight if he wishes to observe the airplane continuously. In a department store, either the first or second methods of flight will prove practical and each method is relatively safe and silent.

Turning now to Figs. 1 and 4, I have shown an additional structure which takes the form of a pneumatic control mechanism similar to that disclosed in my copending application Serial No. 238,116, filed July 23, 1951, and entitled Pressure Flight Control for Miniature Airplanes. The details of this pneumatic control are disclosed in the aforementioned applicationand they are not criticalto the instant "invention. Accordingly, it is sufficient to say that a second elongated, hollow airtube 23 is also slidably received by th guide clip 13 and is joined, at one end, .to a pneumatic control mechanism 24' which bears upon the adjustable elevator G. The opposite end of this air tube 23 leads, either directly or via the pylon l8, to a resilient and compressible hollow air bulb such as is shown at 25 in Fig. {1. Because the pneumatic control 24 and the adjustable elevator 6 are joined to move one with another, the compression and expansion of the hollow air bulb 25 will, manipulate the elevator'fi. Thus, asqueeze on the bulb 25 will impress an increased pressure upon the pneumatic control 24% toflift the elevator 5 and cause the airplane i to climb. Similarly, if the air bulb 25 is released, a decreased pressure will exist within the control 24 and the air tube 23 to lower the elevator 6 and cause the airplane to dive.

To allow the operator to simulate the movements and manipulations of the control stick in a full-scale airplane, I have provided a miniature control'stick or lever 26 which is pivoted, as at 21, to the aforementioned base member l4; Additionally, a lateral arm 28 is provided with an ad justment screw 23 which bears upon a clip spring 558. The spring 3 3, in turn, is limited in movement by a lip 31 overhanging the spring and joined, at one end thereof, to the base M. The spring so serves as a bias for the control stick 25 to move it to an intermediate position against the compressive and resilient force of the air bulb 25. Before the airplane l is flown, the

adjustment screw 29 is turned until the elevator 6 is at an intermediate position for straight'and level flight while the control stick 26 defines the position of Fig. 4. Thereafter, if the controlistick hollow air tubes arranged '26 is moved through the are 32, the spring. is compressed, the air bulb 25' is allowedto expand, and'th'e pneumatic control 24' lowers the elevator 6 to place the airplane in a dive. Similarly, if the control stick 26 is moved'through the are 32, the air bulb 25 is squeezed or compressed to force air pressure through the air tube 23 and cause the pneumatic control 24 to raise the elevator 6 and define a climb position.

In'the more complex speed and direction control embodiment of my invention shown in Fig. 4, the operator 'againmay utilize the pylon l8 or not, as he desires. In either event, the operator possesses complete control over the miniature airplan'e'l to'allow safe operation indoors. Furthermore, the response of the throttle lever l5 and ccntrolstick 26 is similar to the response of an actual throttle and anactual stick in a full size airplane; That is to say, a'manipulation of the control stick 26 about the pivotZ'! will cause the airplaneto climb or dive'in flight while a'manipulation of throttle lever IE will slow or'speed'the motor as desired. Accordingly, I have termed'the combined throttle and control stick structure an actuation mechanism. After some experience, the average school age child or young'adult will be able to maneuver and manipulate the miniature airplane I to perform various acrobatics of a type similar to those possible with the wire and reel controls of my prior Patents 2,292,416 and.

In better service of my inventive objects, the two elongated pressure tubes 9 and 23 are formed from a light plastic material so the weight thereof and the air drag thereupon will not tend to hold the airplane back or pull it inwardly during flight. This light tubing, in combinationwith the light weight .airmotor I, serve materially to 'reducethe hazard'of flying the airplane in a crowded department store. Furthermore, as previously mentioned, these features provide a captive type miniature airplane which is safe, relatively silent, and easy to control. These safety features, in combination, allow my miniature airplane to be flown in a department store for purposes of demonstration, thereby materially to increase the sales volume and to'provide'a less expensive hobby for school age children.

.I claim:

1. In combination with a captive miniature airplane capable of sustained flight, air driven motor means for powering said airplane in flight, pneumatic control means for varying'the flight pattern of said airplane, and a pairof mated elongated sideby side each havinga first and a second end, said air tube first ends being secured at a common point upon said airplane to limit the flight path thereof and being joined, respectively, one to said air driven motor and one to said pneumatic control means.

2. In combination with a captive miniature airplane capable of sustained flight, air driven motor means for powering said airplane in flight, pneumatic control means for varying the flight pattern of said airplane, a pair of mated elongated hollow air tubes arranged side by side each having a first and a second end, said air tube first eri'ds being secured at a common point upon said airplane to limit the flight path thereof and being joined, respectively, one to said air driven motor and one to said pneumatic control means, and air actuation means joined to said air tube second ends, respectively, to actuate said motor and to impress a preselected air pressure upon said pneumatic control means, said air actu-+ 'ation means including a lever means biased to 1 adjustable elevator, an air driven motor for powering the plane in flight, said motor being car ried by said fuselage, and a fluid operated control for said adjustable elevator, said airplane being capable of self-sustained flight, of a flight limiting flexible tube joined at a first end to said fluid operated control and leading to a supply of fluid under pressure at a second end of said tube, and a manual control device including a handle and pressure varying means actuated by said handle arranged adjacent the second end of said tube for actuating the fluid operated control in said airplane by the variance in pressure within said tube.

4. The combination with a captive miniature airplane adapted to traverse a circular flight path,

said airplane having an elongated fuselage, flight sustaining surfaces including lateral wing element, and control surfaces including an adjustable elevator, an air driven motor for powering the plane in flight, said motor being carried by said fuselage, and a fluid operated control for said adjustable elevator, said airplane being capasic of self-sustained flight, of a flight limiting flexible tube joined at a first end to said fluid operated control and leading to a supply of fluid under pressure at a second end of said tube, and a clip detachably mounted on said wing element and spaced laterally from the fuselage, gripping an intermediate portion of said tube thereby.

5. The combination with a captive miniature airplane adapted to traverse a circular flight path, said airplane having an elongated fuselage, flight sustaining surfaces including a lateral wing element, and control surfaces including an adjustable elevator, an air driven motor for powering the plane in flight, said motor being carried by said fuselage, and a fluid operated control for said adjustable elevator, said airplane being capable of self-sustained flight, of a flight limiting flexible tube joined at a. first end to said fluid operated control and leading to a supply of fluid under pressure at a second end of said tube, and a securing device mounted on said wing element and spaced laterally from the fuselage, gripping an intermediate portion of said tube thereby.

6. The combination with a captive miniature airplane adapted to traverse a circular flight path, said airplane having an elongated fuselage, flight sustaining surfaces including a lateral wing element, and control surfaces including an adjustable elevator, a motor and a fluid operated control for said adjustable elevator, said airplane being capable of self-sustained flight, of a flight limiting flexible tube joined at a first end to said fluid operated control and leading to a supply of fluid under pressure at a second end of said tube, a securing device mounted on said wing element and spaced laterally from the fuselage, gripping an intermediate portion of said tube thereby, a manual control device including pressure varying means arranged adjacent the second end of said tube for actuating the fluid operated control in said airplane by the variance in pressure within said tube, a vertically disposed elongated stiif fixed tubular pylon encircling said tube at a point intermediate said manual control device and the first end of said tube to define a center of radius for the circular path of flight of said airplane, said motor being fluid driven, a second flexible tube joined at a first end to said motor and leading to a supply of fluid at a second end of said tube, a manually actuated valve for regulating flow of fluid through said second flexible tube, said manually actuated valve for said second tube and the manual control device being arranged immediately adjacent each other, said second flexible tube lying alongside the flight limiting flexible tube, being coextensive therewith and passing successively from said second end thereof through said pylon and said securing device on the wing of the airplane.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,305,842 'I'oney June 3, 1919 1,450,232 Fox Apr. 3, 1923 1,497,555 Donaldson et a1. June 10, 1924 1,641,707 Strigl Sept. 6, 1927 1,796,157 Moore Mar. 10, 1931 2,364,233 Morey Dec. 5, 1944 2,406,874 Walker Sept. 3, 1946 2,426,259 Christiansen Aug. 26, 1947 2,484,463 Schaad Oct. 11, 1949 2,559,049 St. Clair July 3, 1951 FOREIGN PATENTS Number Country Date 723,043 Germany July .27, 1942 

